From f32c687f03e9764e55831d894b719fdf0104cf25 Mon Sep 17 00:00:00 2001 From: Ben Burdette Date: Wed, 28 Apr 2021 15:50:11 -0600 Subject: move repl.cc to libcmd for linkage --- src/libcmd/command.cc | 37 +++ src/libcmd/local.mk | 6 +- src/libcmd/repl.cc | 832 ++++++++++++++++++++++++++++++++++++++++++++++++++ src/nix/repl.cc | 832 -------------------------------------------------- 4 files changed, 872 insertions(+), 835 deletions(-) create mode 100644 src/libcmd/repl.cc delete mode 100644 src/nix/repl.cc diff --git a/src/libcmd/command.cc b/src/libcmd/command.cc index 644c9c3b0..d790bb51d 100644 --- a/src/libcmd/command.cc +++ b/src/libcmd/command.cc @@ -54,6 +54,7 @@ void StoreCommand::run() run(getStore()); } +/* EvalCommand::EvalCommand() { addFlag({ @@ -77,6 +78,42 @@ ref EvalCommand::getEvalState() } return ref(evalState); } +*/ +EvalCommand::EvalCommand() +{ + addFlag({ + .longName = "debugger", + .description = "start an interactive environment if evaluation fails", + .handler = {&startReplOnEvalErrors, true}, + }); +} +// ref EvalCommand::getEvalState() +// { +// if (!evalState) +// evalState = std::make_shared(searchPath, getStore()); +// return ref(evalState); +// } +extern std::function & env)> debuggerHook; + +ref EvalCommand::getEvalState() +{ + if (!evalState) { + evalState = std::make_shared(searchPath, getStore()); + if (startReplOnEvalErrors) + debuggerHook = [evalState{ref(evalState)}](const Error & error, const std::map & env) { + printError("%s\n\n" ANSI_BOLD "Starting REPL to allow you to inspect the current state of the evaluator.\n" ANSI_NORMAL, error.what()); + runRepl(evalState, env); + }; + } + return ref(evalState); +} + +EvalCommand::~EvalCommand() +{ + if (evalState) + evalState->printStats(); +} + RealisedPathsCommand::RealisedPathsCommand(bool recursive) : recursive(recursive) diff --git a/src/libcmd/local.mk b/src/libcmd/local.mk index ab0e0e43d..c282499b1 100644 --- a/src/libcmd/local.mk +++ b/src/libcmd/local.mk @@ -6,10 +6,10 @@ libcmd_DIR := $(d) libcmd_SOURCES := $(wildcard $(d)/*.cc) -libcmd_CXXFLAGS += -I src/libutil -I src/libstore -I src/libexpr -I src/libmain -I src/libfetchers +libcmd_CXXFLAGS += -I src/libutil -I src/libstore -I src/libexpr -I src/libmain -I src/libfetchers -I src/nix -libcmd_LDFLAGS = -llowdown +libcmd_LDFLAGS = $(EDITLINE_LIBS) -llowdown -libcmd_LIBS = libstore libutil libexpr libmain libfetchers +libcmd_LIBS = libstore libutil libexpr libmain libfetchers libnix libwut $(eval $(call install-file-in, $(d)/nix-cmd.pc, $(prefix)/lib/pkgconfig, 0644)) diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc new file mode 100644 index 000000000..b1f250e73 --- /dev/null +++ b/src/libcmd/repl.cc @@ -0,0 +1,832 @@ +#include +#include +#include +#include + +#include + +#ifdef READLINE +#include +#include +#else +// editline < 1.15.2 don't wrap their API for C++ usage +// (added in https://github.com/troglobit/editline/commit/91398ceb3427b730995357e9d120539fb9bb7461). +// This results in linker errors due to to name-mangling of editline C symbols. +// For compatibility with these versions, we wrap the API here +// (wrapping multiple times on newer versions is no problem). +extern "C" { +#include +} +#endif + +#include "ansicolor.hh" +#include "shared.hh" +#include "eval.hh" +#include "eval-inline.hh" +#include "attr-path.hh" +#include "store-api.hh" +#include "common-eval-args.hh" +#include "get-drvs.hh" +#include "derivations.hh" +#include "affinity.hh" +#include "globals.hh" +#include "command.hh" +#include "finally.hh" +#include "markdown.hh" + +#if HAVE_BOEHMGC +#define GC_INCLUDE_NEW +#include +#endif + +namespace nix { + +struct NixRepl + #if HAVE_BOEHMGC + : gc + #endif +{ + string curDir; + ref state; + Bindings * autoArgs; + + Strings loadedFiles; + + const static int envSize = 32768; + StaticEnv staticEnv; + Env * env; + int displ; + StringSet varNames; + + const Path historyFile; + + NixRepl(ref state); + ~NixRepl(); + void mainLoop(const std::vector & files); + StringSet completePrefix(string prefix); + bool getLine(string & input, const std::string &prompt); + StorePath getDerivationPath(Value & v); + bool processLine(string line); + void loadFile(const Path & path); + void initEnv(); + void reloadFiles(); + void addAttrsToScope(Value & attrs); + void addVarToScope(const Symbol & name, Value * v); + Expr * parseString(string s); + void evalString(string s, Value & v); + + typedef set ValuesSeen; + std::ostream & printValue(std::ostream & str, Value & v, unsigned int maxDepth); + std::ostream & printValue(std::ostream & str, Value & v, unsigned int maxDepth, ValuesSeen & seen); +}; + + +string removeWhitespace(string s) +{ + s = chomp(s); + size_t n = s.find_first_not_of(" \n\r\t"); + if (n != string::npos) s = string(s, n); + return s; +} + + +NixRepl::NixRepl(ref state) + : state(state) + , staticEnv(false, &state->staticBaseEnv) + , historyFile(getDataDir() + "/nix/repl-history") +{ + curDir = absPath("."); +} + + +NixRepl::~NixRepl() +{ + write_history(historyFile.c_str()); +} + +static NixRepl * curRepl; // ugly + +static char * completionCallback(char * s, int *match) { + auto possible = curRepl->completePrefix(s); + if (possible.size() == 1) { + *match = 1; + auto *res = strdup(possible.begin()->c_str() + strlen(s)); + if (!res) throw Error("allocation failure"); + return res; + } else if (possible.size() > 1) { + auto checkAllHaveSameAt = [&](size_t pos) { + auto &first = *possible.begin(); + for (auto &p : possible) { + if (p.size() <= pos || p[pos] != first[pos]) + return false; + } + return true; + }; + size_t start = strlen(s); + size_t len = 0; + while (checkAllHaveSameAt(start + len)) ++len; + if (len > 0) { + *match = 1; + auto *res = strdup(std::string(*possible.begin(), start, len).c_str()); + if (!res) throw Error("allocation failure"); + return res; + } + } + + *match = 0; + return nullptr; +} + +static int listPossibleCallback(char *s, char ***avp) { + auto possible = curRepl->completePrefix(s); + + if (possible.size() > (INT_MAX / sizeof(char*))) + throw Error("too many completions"); + + int ac = 0; + char **vp = nullptr; + + auto check = [&](auto *p) { + if (!p) { + if (vp) { + while (--ac >= 0) + free(vp[ac]); + free(vp); + } + throw Error("allocation failure"); + } + return p; + }; + + vp = check((char **)malloc(possible.size() * sizeof(char*))); + + for (auto & p : possible) + vp[ac++] = check(strdup(p.c_str())); + + *avp = vp; + + return ac; +} + +namespace { + // Used to communicate to NixRepl::getLine whether a signal occurred in ::readline. + volatile sig_atomic_t g_signal_received = 0; + + void sigintHandler(int signo) { + g_signal_received = signo; + } +} + +void NixRepl::mainLoop(const std::vector & files) +{ + string error = ANSI_RED "error:" ANSI_NORMAL " "; + std::cout << "Welcome to Nix version " << nixVersion << ". Type :? for help." << std::endl << std::endl; + + if (!files.empty()) { + for (auto & i : files) + loadedFiles.push_back(i); + + reloadFiles(); + if (!loadedFiles.empty()) std::cout << std::endl; + } + + // Allow nix-repl specific settings in .inputrc + rl_readline_name = "nix-repl"; + createDirs(dirOf(historyFile)); +#ifndef READLINE + el_hist_size = 1000; +#endif + read_history(historyFile.c_str()); + curRepl = this; +#ifndef READLINE + rl_set_complete_func(completionCallback); + rl_set_list_possib_func(listPossibleCallback); +#endif + + std::string input; + + while (true) { + // When continuing input from previous lines, don't print a prompt, just align to the same + // number of chars as the prompt. + if (!getLine(input, input.empty() ? "nix-repl> " : " ")) + break; + + try { + if (!removeWhitespace(input).empty() && !processLine(input)) return; + } catch (ParseError & e) { + if (e.msg().find("unexpected end of file") != std::string::npos) { + // For parse errors on incomplete input, we continue waiting for the next line of + // input without clearing the input so far. + continue; + } else { + printMsg(lvlError, e.msg()); + } + } catch (Error & e) { + printMsg(lvlError, e.msg()); + } catch (Interrupted & e) { + printMsg(lvlError, e.msg()); + } + + // We handled the current input fully, so we should clear it + // and read brand new input. + input.clear(); + std::cout << std::endl; + } +} + + +bool NixRepl::getLine(string & input, const std::string &prompt) +{ + struct sigaction act, old; + sigset_t savedSignalMask, set; + + auto setupSignals = [&]() { + act.sa_handler = sigintHandler; + sigfillset(&act.sa_mask); + act.sa_flags = 0; + if (sigaction(SIGINT, &act, &old)) + throw SysError("installing handler for SIGINT"); + + sigemptyset(&set); + sigaddset(&set, SIGINT); + if (sigprocmask(SIG_UNBLOCK, &set, &savedSignalMask)) + throw SysError("unblocking SIGINT"); + }; + auto restoreSignals = [&]() { + if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr)) + throw SysError("restoring signals"); + + if (sigaction(SIGINT, &old, 0)) + throw SysError("restoring handler for SIGINT"); + }; + + setupSignals(); + char * s = readline(prompt.c_str()); + Finally doFree([&]() { free(s); }); + restoreSignals(); + + if (g_signal_received) { + g_signal_received = 0; + input.clear(); + return true; + } + + if (!s) + return false; + input += s; + input += '\n'; + return true; +} + + +StringSet NixRepl::completePrefix(string prefix) +{ + StringSet completions; + + size_t start = prefix.find_last_of(" \n\r\t(){}[]"); + std::string prev, cur; + if (start == std::string::npos) { + prev = ""; + cur = prefix; + } else { + prev = std::string(prefix, 0, start + 1); + cur = std::string(prefix, start + 1); + } + + size_t slash, dot; + + if ((slash = cur.rfind('/')) != string::npos) { + try { + auto dir = std::string(cur, 0, slash); + auto prefix2 = std::string(cur, slash + 1); + for (auto & entry : readDirectory(dir == "" ? "/" : dir)) { + if (entry.name[0] != '.' && hasPrefix(entry.name, prefix2)) + completions.insert(prev + dir + "/" + entry.name); + } + } catch (Error &) { + } + } else if ((dot = cur.rfind('.')) == string::npos) { + /* This is a variable name; look it up in the current scope. */ + StringSet::iterator i = varNames.lower_bound(cur); + while (i != varNames.end()) { + if (string(*i, 0, cur.size()) != cur) break; + completions.insert(prev + *i); + i++; + } + } else { + try { + /* This is an expression that should evaluate to an + attribute set. Evaluate it to get the names of the + attributes. */ + string expr(cur, 0, dot); + string cur2 = string(cur, dot + 1); + + Expr * e = parseString(expr); + Value v; + e->eval(*state, *env, v); + state->forceAttrs(v); + + for (auto & i : *v.attrs) { + string name = i.name; + if (string(name, 0, cur2.size()) != cur2) continue; + completions.insert(prev + expr + "." + name); + } + + } catch (ParseError & e) { + // Quietly ignore parse errors. + } catch (EvalError & e) { + // Quietly ignore evaluation errors. + } catch (UndefinedVarError & e) { + // Quietly ignore undefined variable errors. + } + } + + return completions; +} + + +bool isVarName(const string & s) +{ + if (s.size() == 0) return false; + char c = s[0]; + if ((c >= '0' && c <= '9') || c == '-' || c == '\'') return false; + for (auto & i : s) + if (!((i >= 'a' && i <= 'z') || + (i >= 'A' && i <= 'Z') || + (i >= '0' && i <= '9') || + i == '_' || i == '-' || i == '\'')) + return false; + return true; +} + + +StorePath NixRepl::getDerivationPath(Value & v) { + auto drvInfo = getDerivation(*state, v, false); + if (!drvInfo) + throw Error("expression does not evaluate to a derivation, so I can't build it"); + Path drvPathRaw = drvInfo->queryDrvPath(); + if (drvPathRaw == "") + throw Error("expression did not evaluate to a valid derivation (no drv path)"); + StorePath drvPath = state->store->parseStorePath(drvPathRaw); + if (!state->store->isValidPath(drvPath)) + throw Error("expression did not evaluate to a valid derivation (invalid drv path)"); + return drvPath; +} + + +bool NixRepl::processLine(string line) +{ + if (line == "") return true; + + string command, arg; + + if (line[0] == ':') { + size_t p = line.find_first_of(" \n\r\t"); + command = string(line, 0, p); + if (p != string::npos) arg = removeWhitespace(string(line, p)); + } else { + arg = line; + } + + if (command == ":?" || command == ":help") { + // FIXME: convert to Markdown, include in the 'nix repl' manpage. + std::cout + << "The following commands are available:\n" + << "\n" + << " Evaluate and print expression\n" + << " = Bind expression to variable\n" + << " :a Add attributes from resulting set to scope\n" + << " :b Build derivation\n" + << " :e Open the derivation in $EDITOR\n" + << " :i Build derivation, then install result into current profile\n" + << " :l Load Nix expression and add it to scope\n" + << " :p Evaluate and print expression recursively\n" + << " :q Exit nix-repl\n" + << " :r Reload all files\n" + << " :s Build dependencies of derivation, then start nix-shell\n" + << " :t Describe result of evaluation\n" + << " :u Build derivation, then start nix-shell\n" + << " :doc Show documentation of a builtin function\n"; + } + + else if (command == ":a" || command == ":add") { + Value v; + evalString(arg, v); + addAttrsToScope(v); + } + + else if (command == ":l" || command == ":load") { + state->resetFileCache(); + loadFile(arg); + } + + else if (command == ":r" || command == ":reload") { + state->resetFileCache(); + reloadFiles(); + } + + else if (command == ":e" || command == ":edit") { + Value v; + evalString(arg, v); + + Pos pos; + + if (v.type() == nPath || v.type() == nString) { + PathSet context; + auto filename = state->coerceToString(noPos, v, context); + pos.file = state->symbols.create(filename); + } else if (v.isLambda()) { + pos = v.lambda.fun->pos; + } else { + // assume it's a derivation + pos = findDerivationFilename(*state, v, arg); + } + + // Open in EDITOR + auto args = editorFor(pos); + auto editor = args.front(); + args.pop_front(); + runProgram(editor, true, args); + + // Reload right after exiting the editor + state->resetFileCache(); + reloadFiles(); + } + + else if (command == ":t") { + Value v; + evalString(arg, v); + std::cout << showType(v) << std::endl; + + } else if (command == ":u") { + Value v, f, result; + evalString(arg, v); + evalString("drv: (import {}).runCommand \"shell\" { buildInputs = [ drv ]; } \"\"", f); + state->callFunction(f, v, result, Pos()); + + StorePath drvPath = getDerivationPath(result); + runProgram(settings.nixBinDir + "/nix-shell", true, {state->store->printStorePath(drvPath)}); + } + + else if (command == ":b" || command == ":i" || command == ":s") { + Value v; + evalString(arg, v); + StorePath drvPath = getDerivationPath(v); + Path drvPathRaw = state->store->printStorePath(drvPath); + + if (command == ":b") { + /* We could do the build in this process using buildPaths(), + but doing it in a child makes it easier to recover from + problems / SIGINT. */ + try { + runProgram(settings.nixBinDir + "/nix", true, {"build", "--no-link", drvPathRaw}); + auto drv = state->store->readDerivation(drvPath); + std::cout << std::endl << "this derivation produced the following outputs:" << std::endl; + for (auto & i : drv.outputsAndOptPaths(*state->store)) + std::cout << fmt(" %s -> %s\n", i.first, state->store->printStorePath(*i.second.second)); + } catch (ExecError &) { + } + } else if (command == ":i") { + runProgram(settings.nixBinDir + "/nix-env", true, {"-i", drvPathRaw}); + } else { + runProgram(settings.nixBinDir + "/nix-shell", true, {drvPathRaw}); + } + } + + else if (command == ":p" || command == ":print") { + Value v; + evalString(arg, v); + printValue(std::cout, v, 1000000000) << std::endl; + } + + else if (command == ":q" || command == ":quit") + return false; + + else if (command == ":doc") { + Value v; + evalString(arg, v); + if (auto doc = state->getDoc(v)) { + std::string markdown; + + if (!doc->args.empty() && doc->name) { + auto args = doc->args; + for (auto & arg : args) + arg = "*" + arg + "*"; + + markdown += + "**Synopsis:** `builtins." + (std::string) (*doc->name) + "` " + + concatStringsSep(" ", args) + "\n\n"; + } + + markdown += trim(stripIndentation(doc->doc)); + + std::cout << renderMarkdownToTerminal(markdown); + } else + throw Error("value does not have documentation"); + } + + else if (command != "") + throw Error("unknown command '%1%'", command); + + else { + size_t p = line.find('='); + string name; + if (p != string::npos && + p < line.size() && + line[p + 1] != '=' && + isVarName(name = removeWhitespace(string(line, 0, p)))) + { + Expr * e = parseString(string(line, p + 1)); + Value *v = new Value(*state->allocValue()); + v->mkThunk(env, e); + addVarToScope(state->symbols.create(name), v); + } else { + Value v; + evalString(line, v); + printValue(std::cout, v, 1) << std::endl; + } + } + + return true; +} + + +void NixRepl::loadFile(const Path & path) +{ + loadedFiles.remove(path); + loadedFiles.push_back(path); + Value v, v2; + state->evalFile(lookupFileArg(*state, path), v); + state->autoCallFunction(*autoArgs, v, v2); + addAttrsToScope(v2); +} + + +void NixRepl::initEnv() +{ + env = &state->allocEnv(envSize); + env->up = &state->baseEnv; + displ = 0; + staticEnv.vars.clear(); + + varNames.clear(); + for (auto & i : state->staticBaseEnv.vars) + varNames.insert(i.first); +} + + +void NixRepl::reloadFiles() +{ + initEnv(); + + Strings old = loadedFiles; + loadedFiles.clear(); + + bool first = true; + for (auto & i : old) { + if (!first) std::cout << std::endl; + first = false; + std::cout << format("Loading '%1%'...") % i << std::endl; + loadFile(i); + } +} + + +void NixRepl::addAttrsToScope(Value & attrs) +{ + state->forceAttrs(attrs); + for (auto & i : *attrs.attrs) + addVarToScope(i.name, i.value); + std::cout << format("Added %1% variables.") % attrs.attrs->size() << std::endl; +} + + +void NixRepl::addVarToScope(const Symbol & name, Value * v) +{ + if (displ >= envSize) + throw Error("environment full; cannot add more variables"); + staticEnv.vars[name] = displ; + env->values[displ++] = v; + varNames.insert((string) name); +} + + +Expr * NixRepl::parseString(string s) +{ + Expr * e = state->parseExprFromString(s, curDir, staticEnv); + return e; +} + + +void NixRepl::evalString(string s, Value & v) +{ + Expr * e = parseString(s); + e->eval(*state, *env, v); + state->forceValue(v); +} + + +std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int maxDepth) +{ + ValuesSeen seen; + return printValue(str, v, maxDepth, seen); +} + + +std::ostream & printStringValue(std::ostream & str, const char * string) { + str << "\""; + for (const char * i = string; *i; i++) + if (*i == '\"' || *i == '\\') str << "\\" << *i; + else if (*i == '\n') str << "\\n"; + else if (*i == '\r') str << "\\r"; + else if (*i == '\t') str << "\\t"; + else str << *i; + str << "\""; + return str; +} + + +// FIXME: lot of cut&paste from Nix's eval.cc. +std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int maxDepth, ValuesSeen & seen) +{ + str.flush(); + checkInterrupt(); + + state->forceValue(v); + + switch (v.type()) { + + case nInt: + str << ANSI_CYAN << v.integer << ANSI_NORMAL; + break; + + case nBool: + str << ANSI_CYAN << (v.boolean ? "true" : "false") << ANSI_NORMAL; + break; + + case nString: + str << ANSI_YELLOW; + printStringValue(str, v.string.s); + str << ANSI_NORMAL; + break; + + case nPath: + str << ANSI_GREEN << v.path << ANSI_NORMAL; // !!! escaping? + break; + + case nNull: + str << ANSI_CYAN "null" ANSI_NORMAL; + break; + + case nAttrs: { + seen.insert(&v); + + bool isDrv = state->isDerivation(v); + + if (isDrv) { + str << "«derivation "; + Bindings::iterator i = v.attrs->find(state->sDrvPath); + PathSet context; + Path drvPath = i != v.attrs->end() ? state->coerceToPath(*i->pos, *i->value, context) : "???"; + str << drvPath << "»"; + } + + else if (maxDepth > 0) { + str << "{ "; + + typedef std::map Sorted; + Sorted sorted; + for (auto & i : *v.attrs) + sorted[i.name] = i.value; + + for (auto & i : sorted) { + if (isVarName(i.first)) + str << i.first; + else + printStringValue(str, i.first.c_str()); + str << " = "; + if (seen.find(i.second) != seen.end()) + str << "«repeated»"; + else + try { + printValue(str, *i.second, maxDepth - 1, seen); + } catch (AssertionError & e) { + str << ANSI_RED "«error: " << e.msg() << "»" ANSI_NORMAL; + } + str << "; "; + } + + str << "}"; + } else + str << "{ ... }"; + + break; + } + + case nList: + seen.insert(&v); + + str << "[ "; + if (maxDepth > 0) + for (unsigned int n = 0; n < v.listSize(); ++n) { + if (seen.find(v.listElems()[n]) != seen.end()) + str << "«repeated»"; + else + try { + printValue(str, *v.listElems()[n], maxDepth - 1, seen); + } catch (AssertionError & e) { + str << ANSI_RED "«error: " << e.msg() << "»" ANSI_NORMAL; + } + str << " "; + } + else + str << "... "; + str << "]"; + break; + + case nFunction: + if (v.isLambda()) { + std::ostringstream s; + s << v.lambda.fun->pos; + str << ANSI_BLUE "«lambda @ " << filterANSIEscapes(s.str()) << "»" ANSI_NORMAL; + } else if (v.isPrimOp()) { + str << ANSI_MAGENTA "«primop»" ANSI_NORMAL; + } else if (v.isPrimOpApp()) { + str << ANSI_BLUE "«primop-app»" ANSI_NORMAL; + } else { + abort(); + } + break; + + case nFloat: + str << v.fpoint; + break; + + default: + str << ANSI_RED "«unknown»" ANSI_NORMAL; + break; + } + + return str; +} + +void runRepl( + ref evalState, + const std::map & extraEnv) +{ + auto repl = std::make_unique(evalState); + + repl->initEnv(); + + std::set names; + + for (auto & [name, value] : extraEnv) { + names.insert(ANSI_BOLD + name + ANSI_NORMAL); + repl->addVarToScope(repl->state->symbols.create(name), value); + } + + printError("The following extra variables are in scope: %s\n", concatStringsSep(", ", names)); + + repl->mainLoop({}); +} + +struct CmdRepl : StoreCommand, MixEvalArgs +{ + std::vector files; + + CmdRepl() + { + expectArgs({ + .label = "files", + .handler = {&files}, + .completer = completePath + }); + } + + std::string description() override + { + return "start an interactive environment for evaluating Nix expressions"; + } + + std::string doc() override + { + return + #include "repl.md" + ; + } + + void run(ref store) override + { + evalSettings.pureEval = false; + + auto evalState = make_ref(searchPath, store); + + auto repl = std::make_unique(evalState); + repl->autoArgs = getAutoArgs(*repl->state); + repl->mainLoop(files); + } +}; + +static auto rCmdRepl = registerCommand("repl"); + +} diff --git a/src/nix/repl.cc b/src/nix/repl.cc deleted file mode 100644 index b1f250e73..000000000 --- a/src/nix/repl.cc +++ /dev/null @@ -1,832 +0,0 @@ -#include -#include -#include -#include - -#include - -#ifdef READLINE -#include -#include -#else -// editline < 1.15.2 don't wrap their API for C++ usage -// (added in https://github.com/troglobit/editline/commit/91398ceb3427b730995357e9d120539fb9bb7461). -// This results in linker errors due to to name-mangling of editline C symbols. -// For compatibility with these versions, we wrap the API here -// (wrapping multiple times on newer versions is no problem). -extern "C" { -#include -} -#endif - -#include "ansicolor.hh" -#include "shared.hh" -#include "eval.hh" -#include "eval-inline.hh" -#include "attr-path.hh" -#include "store-api.hh" -#include "common-eval-args.hh" -#include "get-drvs.hh" -#include "derivations.hh" -#include "affinity.hh" -#include "globals.hh" -#include "command.hh" -#include "finally.hh" -#include "markdown.hh" - -#if HAVE_BOEHMGC -#define GC_INCLUDE_NEW -#include -#endif - -namespace nix { - -struct NixRepl - #if HAVE_BOEHMGC - : gc - #endif -{ - string curDir; - ref state; - Bindings * autoArgs; - - Strings loadedFiles; - - const static int envSize = 32768; - StaticEnv staticEnv; - Env * env; - int displ; - StringSet varNames; - - const Path historyFile; - - NixRepl(ref state); - ~NixRepl(); - void mainLoop(const std::vector & files); - StringSet completePrefix(string prefix); - bool getLine(string & input, const std::string &prompt); - StorePath getDerivationPath(Value & v); - bool processLine(string line); - void loadFile(const Path & path); - void initEnv(); - void reloadFiles(); - void addAttrsToScope(Value & attrs); - void addVarToScope(const Symbol & name, Value * v); - Expr * parseString(string s); - void evalString(string s, Value & v); - - typedef set ValuesSeen; - std::ostream & printValue(std::ostream & str, Value & v, unsigned int maxDepth); - std::ostream & printValue(std::ostream & str, Value & v, unsigned int maxDepth, ValuesSeen & seen); -}; - - -string removeWhitespace(string s) -{ - s = chomp(s); - size_t n = s.find_first_not_of(" \n\r\t"); - if (n != string::npos) s = string(s, n); - return s; -} - - -NixRepl::NixRepl(ref state) - : state(state) - , staticEnv(false, &state->staticBaseEnv) - , historyFile(getDataDir() + "/nix/repl-history") -{ - curDir = absPath("."); -} - - -NixRepl::~NixRepl() -{ - write_history(historyFile.c_str()); -} - -static NixRepl * curRepl; // ugly - -static char * completionCallback(char * s, int *match) { - auto possible = curRepl->completePrefix(s); - if (possible.size() == 1) { - *match = 1; - auto *res = strdup(possible.begin()->c_str() + strlen(s)); - if (!res) throw Error("allocation failure"); - return res; - } else if (possible.size() > 1) { - auto checkAllHaveSameAt = [&](size_t pos) { - auto &first = *possible.begin(); - for (auto &p : possible) { - if (p.size() <= pos || p[pos] != first[pos]) - return false; - } - return true; - }; - size_t start = strlen(s); - size_t len = 0; - while (checkAllHaveSameAt(start + len)) ++len; - if (len > 0) { - *match = 1; - auto *res = strdup(std::string(*possible.begin(), start, len).c_str()); - if (!res) throw Error("allocation failure"); - return res; - } - } - - *match = 0; - return nullptr; -} - -static int listPossibleCallback(char *s, char ***avp) { - auto possible = curRepl->completePrefix(s); - - if (possible.size() > (INT_MAX / sizeof(char*))) - throw Error("too many completions"); - - int ac = 0; - char **vp = nullptr; - - auto check = [&](auto *p) { - if (!p) { - if (vp) { - while (--ac >= 0) - free(vp[ac]); - free(vp); - } - throw Error("allocation failure"); - } - return p; - }; - - vp = check((char **)malloc(possible.size() * sizeof(char*))); - - for (auto & p : possible) - vp[ac++] = check(strdup(p.c_str())); - - *avp = vp; - - return ac; -} - -namespace { - // Used to communicate to NixRepl::getLine whether a signal occurred in ::readline. - volatile sig_atomic_t g_signal_received = 0; - - void sigintHandler(int signo) { - g_signal_received = signo; - } -} - -void NixRepl::mainLoop(const std::vector & files) -{ - string error = ANSI_RED "error:" ANSI_NORMAL " "; - std::cout << "Welcome to Nix version " << nixVersion << ". Type :? for help." << std::endl << std::endl; - - if (!files.empty()) { - for (auto & i : files) - loadedFiles.push_back(i); - - reloadFiles(); - if (!loadedFiles.empty()) std::cout << std::endl; - } - - // Allow nix-repl specific settings in .inputrc - rl_readline_name = "nix-repl"; - createDirs(dirOf(historyFile)); -#ifndef READLINE - el_hist_size = 1000; -#endif - read_history(historyFile.c_str()); - curRepl = this; -#ifndef READLINE - rl_set_complete_func(completionCallback); - rl_set_list_possib_func(listPossibleCallback); -#endif - - std::string input; - - while (true) { - // When continuing input from previous lines, don't print a prompt, just align to the same - // number of chars as the prompt. - if (!getLine(input, input.empty() ? "nix-repl> " : " ")) - break; - - try { - if (!removeWhitespace(input).empty() && !processLine(input)) return; - } catch (ParseError & e) { - if (e.msg().find("unexpected end of file") != std::string::npos) { - // For parse errors on incomplete input, we continue waiting for the next line of - // input without clearing the input so far. - continue; - } else { - printMsg(lvlError, e.msg()); - } - } catch (Error & e) { - printMsg(lvlError, e.msg()); - } catch (Interrupted & e) { - printMsg(lvlError, e.msg()); - } - - // We handled the current input fully, so we should clear it - // and read brand new input. - input.clear(); - std::cout << std::endl; - } -} - - -bool NixRepl::getLine(string & input, const std::string &prompt) -{ - struct sigaction act, old; - sigset_t savedSignalMask, set; - - auto setupSignals = [&]() { - act.sa_handler = sigintHandler; - sigfillset(&act.sa_mask); - act.sa_flags = 0; - if (sigaction(SIGINT, &act, &old)) - throw SysError("installing handler for SIGINT"); - - sigemptyset(&set); - sigaddset(&set, SIGINT); - if (sigprocmask(SIG_UNBLOCK, &set, &savedSignalMask)) - throw SysError("unblocking SIGINT"); - }; - auto restoreSignals = [&]() { - if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr)) - throw SysError("restoring signals"); - - if (sigaction(SIGINT, &old, 0)) - throw SysError("restoring handler for SIGINT"); - }; - - setupSignals(); - char * s = readline(prompt.c_str()); - Finally doFree([&]() { free(s); }); - restoreSignals(); - - if (g_signal_received) { - g_signal_received = 0; - input.clear(); - return true; - } - - if (!s) - return false; - input += s; - input += '\n'; - return true; -} - - -StringSet NixRepl::completePrefix(string prefix) -{ - StringSet completions; - - size_t start = prefix.find_last_of(" \n\r\t(){}[]"); - std::string prev, cur; - if (start == std::string::npos) { - prev = ""; - cur = prefix; - } else { - prev = std::string(prefix, 0, start + 1); - cur = std::string(prefix, start + 1); - } - - size_t slash, dot; - - if ((slash = cur.rfind('/')) != string::npos) { - try { - auto dir = std::string(cur, 0, slash); - auto prefix2 = std::string(cur, slash + 1); - for (auto & entry : readDirectory(dir == "" ? "/" : dir)) { - if (entry.name[0] != '.' && hasPrefix(entry.name, prefix2)) - completions.insert(prev + dir + "/" + entry.name); - } - } catch (Error &) { - } - } else if ((dot = cur.rfind('.')) == string::npos) { - /* This is a variable name; look it up in the current scope. */ - StringSet::iterator i = varNames.lower_bound(cur); - while (i != varNames.end()) { - if (string(*i, 0, cur.size()) != cur) break; - completions.insert(prev + *i); - i++; - } - } else { - try { - /* This is an expression that should evaluate to an - attribute set. Evaluate it to get the names of the - attributes. */ - string expr(cur, 0, dot); - string cur2 = string(cur, dot + 1); - - Expr * e = parseString(expr); - Value v; - e->eval(*state, *env, v); - state->forceAttrs(v); - - for (auto & i : *v.attrs) { - string name = i.name; - if (string(name, 0, cur2.size()) != cur2) continue; - completions.insert(prev + expr + "." + name); - } - - } catch (ParseError & e) { - // Quietly ignore parse errors. - } catch (EvalError & e) { - // Quietly ignore evaluation errors. - } catch (UndefinedVarError & e) { - // Quietly ignore undefined variable errors. - } - } - - return completions; -} - - -bool isVarName(const string & s) -{ - if (s.size() == 0) return false; - char c = s[0]; - if ((c >= '0' && c <= '9') || c == '-' || c == '\'') return false; - for (auto & i : s) - if (!((i >= 'a' && i <= 'z') || - (i >= 'A' && i <= 'Z') || - (i >= '0' && i <= '9') || - i == '_' || i == '-' || i == '\'')) - return false; - return true; -} - - -StorePath NixRepl::getDerivationPath(Value & v) { - auto drvInfo = getDerivation(*state, v, false); - if (!drvInfo) - throw Error("expression does not evaluate to a derivation, so I can't build it"); - Path drvPathRaw = drvInfo->queryDrvPath(); - if (drvPathRaw == "") - throw Error("expression did not evaluate to a valid derivation (no drv path)"); - StorePath drvPath = state->store->parseStorePath(drvPathRaw); - if (!state->store->isValidPath(drvPath)) - throw Error("expression did not evaluate to a valid derivation (invalid drv path)"); - return drvPath; -} - - -bool NixRepl::processLine(string line) -{ - if (line == "") return true; - - string command, arg; - - if (line[0] == ':') { - size_t p = line.find_first_of(" \n\r\t"); - command = string(line, 0, p); - if (p != string::npos) arg = removeWhitespace(string(line, p)); - } else { - arg = line; - } - - if (command == ":?" || command == ":help") { - // FIXME: convert to Markdown, include in the 'nix repl' manpage. - std::cout - << "The following commands are available:\n" - << "\n" - << " Evaluate and print expression\n" - << " = Bind expression to variable\n" - << " :a Add attributes from resulting set to scope\n" - << " :b Build derivation\n" - << " :e Open the derivation in $EDITOR\n" - << " :i Build derivation, then install result into current profile\n" - << " :l Load Nix expression and add it to scope\n" - << " :p Evaluate and print expression recursively\n" - << " :q Exit nix-repl\n" - << " :r Reload all files\n" - << " :s Build dependencies of derivation, then start nix-shell\n" - << " :t Describe result of evaluation\n" - << " :u Build derivation, then start nix-shell\n" - << " :doc Show documentation of a builtin function\n"; - } - - else if (command == ":a" || command == ":add") { - Value v; - evalString(arg, v); - addAttrsToScope(v); - } - - else if (command == ":l" || command == ":load") { - state->resetFileCache(); - loadFile(arg); - } - - else if (command == ":r" || command == ":reload") { - state->resetFileCache(); - reloadFiles(); - } - - else if (command == ":e" || command == ":edit") { - Value v; - evalString(arg, v); - - Pos pos; - - if (v.type() == nPath || v.type() == nString) { - PathSet context; - auto filename = state->coerceToString(noPos, v, context); - pos.file = state->symbols.create(filename); - } else if (v.isLambda()) { - pos = v.lambda.fun->pos; - } else { - // assume it's a derivation - pos = findDerivationFilename(*state, v, arg); - } - - // Open in EDITOR - auto args = editorFor(pos); - auto editor = args.front(); - args.pop_front(); - runProgram(editor, true, args); - - // Reload right after exiting the editor - state->resetFileCache(); - reloadFiles(); - } - - else if (command == ":t") { - Value v; - evalString(arg, v); - std::cout << showType(v) << std::endl; - - } else if (command == ":u") { - Value v, f, result; - evalString(arg, v); - evalString("drv: (import {}).runCommand \"shell\" { buildInputs = [ drv ]; } \"\"", f); - state->callFunction(f, v, result, Pos()); - - StorePath drvPath = getDerivationPath(result); - runProgram(settings.nixBinDir + "/nix-shell", true, {state->store->printStorePath(drvPath)}); - } - - else if (command == ":b" || command == ":i" || command == ":s") { - Value v; - evalString(arg, v); - StorePath drvPath = getDerivationPath(v); - Path drvPathRaw = state->store->printStorePath(drvPath); - - if (command == ":b") { - /* We could do the build in this process using buildPaths(), - but doing it in a child makes it easier to recover from - problems / SIGINT. */ - try { - runProgram(settings.nixBinDir + "/nix", true, {"build", "--no-link", drvPathRaw}); - auto drv = state->store->readDerivation(drvPath); - std::cout << std::endl << "this derivation produced the following outputs:" << std::endl; - for (auto & i : drv.outputsAndOptPaths(*state->store)) - std::cout << fmt(" %s -> %s\n", i.first, state->store->printStorePath(*i.second.second)); - } catch (ExecError &) { - } - } else if (command == ":i") { - runProgram(settings.nixBinDir + "/nix-env", true, {"-i", drvPathRaw}); - } else { - runProgram(settings.nixBinDir + "/nix-shell", true, {drvPathRaw}); - } - } - - else if (command == ":p" || command == ":print") { - Value v; - evalString(arg, v); - printValue(std::cout, v, 1000000000) << std::endl; - } - - else if (command == ":q" || command == ":quit") - return false; - - else if (command == ":doc") { - Value v; - evalString(arg, v); - if (auto doc = state->getDoc(v)) { - std::string markdown; - - if (!doc->args.empty() && doc->name) { - auto args = doc->args; - for (auto & arg : args) - arg = "*" + arg + "*"; - - markdown += - "**Synopsis:** `builtins." + (std::string) (*doc->name) + "` " - + concatStringsSep(" ", args) + "\n\n"; - } - - markdown += trim(stripIndentation(doc->doc)); - - std::cout << renderMarkdownToTerminal(markdown); - } else - throw Error("value does not have documentation"); - } - - else if (command != "") - throw Error("unknown command '%1%'", command); - - else { - size_t p = line.find('='); - string name; - if (p != string::npos && - p < line.size() && - line[p + 1] != '=' && - isVarName(name = removeWhitespace(string(line, 0, p)))) - { - Expr * e = parseString(string(line, p + 1)); - Value *v = new Value(*state->allocValue()); - v->mkThunk(env, e); - addVarToScope(state->symbols.create(name), v); - } else { - Value v; - evalString(line, v); - printValue(std::cout, v, 1) << std::endl; - } - } - - return true; -} - - -void NixRepl::loadFile(const Path & path) -{ - loadedFiles.remove(path); - loadedFiles.push_back(path); - Value v, v2; - state->evalFile(lookupFileArg(*state, path), v); - state->autoCallFunction(*autoArgs, v, v2); - addAttrsToScope(v2); -} - - -void NixRepl::initEnv() -{ - env = &state->allocEnv(envSize); - env->up = &state->baseEnv; - displ = 0; - staticEnv.vars.clear(); - - varNames.clear(); - for (auto & i : state->staticBaseEnv.vars) - varNames.insert(i.first); -} - - -void NixRepl::reloadFiles() -{ - initEnv(); - - Strings old = loadedFiles; - loadedFiles.clear(); - - bool first = true; - for (auto & i : old) { - if (!first) std::cout << std::endl; - first = false; - std::cout << format("Loading '%1%'...") % i << std::endl; - loadFile(i); - } -} - - -void NixRepl::addAttrsToScope(Value & attrs) -{ - state->forceAttrs(attrs); - for (auto & i : *attrs.attrs) - addVarToScope(i.name, i.value); - std::cout << format("Added %1% variables.") % attrs.attrs->size() << std::endl; -} - - -void NixRepl::addVarToScope(const Symbol & name, Value * v) -{ - if (displ >= envSize) - throw Error("environment full; cannot add more variables"); - staticEnv.vars[name] = displ; - env->values[displ++] = v; - varNames.insert((string) name); -} - - -Expr * NixRepl::parseString(string s) -{ - Expr * e = state->parseExprFromString(s, curDir, staticEnv); - return e; -} - - -void NixRepl::evalString(string s, Value & v) -{ - Expr * e = parseString(s); - e->eval(*state, *env, v); - state->forceValue(v); -} - - -std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int maxDepth) -{ - ValuesSeen seen; - return printValue(str, v, maxDepth, seen); -} - - -std::ostream & printStringValue(std::ostream & str, const char * string) { - str << "\""; - for (const char * i = string; *i; i++) - if (*i == '\"' || *i == '\\') str << "\\" << *i; - else if (*i == '\n') str << "\\n"; - else if (*i == '\r') str << "\\r"; - else if (*i == '\t') str << "\\t"; - else str << *i; - str << "\""; - return str; -} - - -// FIXME: lot of cut&paste from Nix's eval.cc. -std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int maxDepth, ValuesSeen & seen) -{ - str.flush(); - checkInterrupt(); - - state->forceValue(v); - - switch (v.type()) { - - case nInt: - str << ANSI_CYAN << v.integer << ANSI_NORMAL; - break; - - case nBool: - str << ANSI_CYAN << (v.boolean ? "true" : "false") << ANSI_NORMAL; - break; - - case nString: - str << ANSI_YELLOW; - printStringValue(str, v.string.s); - str << ANSI_NORMAL; - break; - - case nPath: - str << ANSI_GREEN << v.path << ANSI_NORMAL; // !!! escaping? - break; - - case nNull: - str << ANSI_CYAN "null" ANSI_NORMAL; - break; - - case nAttrs: { - seen.insert(&v); - - bool isDrv = state->isDerivation(v); - - if (isDrv) { - str << "«derivation "; - Bindings::iterator i = v.attrs->find(state->sDrvPath); - PathSet context; - Path drvPath = i != v.attrs->end() ? state->coerceToPath(*i->pos, *i->value, context) : "???"; - str << drvPath << "»"; - } - - else if (maxDepth > 0) { - str << "{ "; - - typedef std::map Sorted; - Sorted sorted; - for (auto & i : *v.attrs) - sorted[i.name] = i.value; - - for (auto & i : sorted) { - if (isVarName(i.first)) - str << i.first; - else - printStringValue(str, i.first.c_str()); - str << " = "; - if (seen.find(i.second) != seen.end()) - str << "«repeated»"; - else - try { - printValue(str, *i.second, maxDepth - 1, seen); - } catch (AssertionError & e) { - str << ANSI_RED "«error: " << e.msg() << "»" ANSI_NORMAL; - } - str << "; "; - } - - str << "}"; - } else - str << "{ ... }"; - - break; - } - - case nList: - seen.insert(&v); - - str << "[ "; - if (maxDepth > 0) - for (unsigned int n = 0; n < v.listSize(); ++n) { - if (seen.find(v.listElems()[n]) != seen.end()) - str << "«repeated»"; - else - try { - printValue(str, *v.listElems()[n], maxDepth - 1, seen); - } catch (AssertionError & e) { - str << ANSI_RED "«error: " << e.msg() << "»" ANSI_NORMAL; - } - str << " "; - } - else - str << "... "; - str << "]"; - break; - - case nFunction: - if (v.isLambda()) { - std::ostringstream s; - s << v.lambda.fun->pos; - str << ANSI_BLUE "«lambda @ " << filterANSIEscapes(s.str()) << "»" ANSI_NORMAL; - } else if (v.isPrimOp()) { - str << ANSI_MAGENTA "«primop»" ANSI_NORMAL; - } else if (v.isPrimOpApp()) { - str << ANSI_BLUE "«primop-app»" ANSI_NORMAL; - } else { - abort(); - } - break; - - case nFloat: - str << v.fpoint; - break; - - default: - str << ANSI_RED "«unknown»" ANSI_NORMAL; - break; - } - - return str; -} - -void runRepl( - ref evalState, - const std::map & extraEnv) -{ - auto repl = std::make_unique(evalState); - - repl->initEnv(); - - std::set names; - - for (auto & [name, value] : extraEnv) { - names.insert(ANSI_BOLD + name + ANSI_NORMAL); - repl->addVarToScope(repl->state->symbols.create(name), value); - } - - printError("The following extra variables are in scope: %s\n", concatStringsSep(", ", names)); - - repl->mainLoop({}); -} - -struct CmdRepl : StoreCommand, MixEvalArgs -{ - std::vector files; - - CmdRepl() - { - expectArgs({ - .label = "files", - .handler = {&files}, - .completer = completePath - }); - } - - std::string description() override - { - return "start an interactive environment for evaluating Nix expressions"; - } - - std::string doc() override - { - return - #include "repl.md" - ; - } - - void run(ref store) override - { - evalSettings.pureEval = false; - - auto evalState = make_ref(searchPath, store); - - auto repl = std::make_unique(evalState); - repl->autoArgs = getAutoArgs(*repl->state); - repl->mainLoop(files); - } -}; - -static auto rCmdRepl = registerCommand("repl"); - -} -- cgit v1.2.3